Page:Encyclopædia Britannica, Ninth Edition, v. 10.djvu/378

Rh 364 lhcrium, and other mammals. The second group (Sarmatian stage) consists of brackish-water beds showing the partial uprise of the bottom of the Vienna basin. It contains (.'cri(ln'unz, Paludina, 1.'issoa, with bones of dolphins, seals, turtles, and fish. The two uppermost divisions (Congeria stage and Belvedere stage), referred to the Pliocene series, are fresh-water formations, showing the ﬁnal freshening and disappearance of the lliocene sea in the south-east of Europe. In Styria and Carinthia the lower Aquitanian or hlediterranean stage bears witness in its plants and lignites to the proximity of lan-l during its formation, while its shells are of fresh and brackish water genera. It has subsequently been upheaved, and the later Miocene strata lie unconformably on its edges. The subterranean movements east of the Alps culminated in the outpouring of enor- mous sheets of traehyte, audcsite, propylite, and basalt in Hungary and along the flanks of the Carpathian chain into Transylvania. ln Croatia the older Miocene marls, with their abundant land-plants, insects, &c., contain two beds of sulphur (the upper 4 to 16 inches thick, the under 10 to 15 inches), which have been worked at l-ladoboj. At llrastrcigg, Buchberg, and elsewhere, coal is worked in the Aquitanian stage in a bed sometimes 65 feet thick. In Tran- sylvania, and along the base of the Carpathian mountains, extensive masses of rock-salt and gypsum are interstratilied in the Tertiary formations. The largest of these, that of Parajd, has a maximum length of about 2500 yards, a breadth of 1800 yards, and a depth nearly 200 yards, and is estimated to contain 3500 millions of cubic feet of salt. GREE‘.'L.-_'D.—-One of the most remarkable geological discoveries of recent times has been that of Miocene plant beds in North Greenland. Heer has described a ﬂora ex- tending at least up to 70° N. lat., containing 137 species, of which 46 are found also in the central European Miocene basins. More than half of the plants are trees, including 30 species of conifers (Seqzzoia, Tlmjopsis, Salisliuria, &c.), besides beeches, oaks, planes, poplars, maples, walnuts, limes, magnolias, and many more. These plants grew on the spot, for their fruits in various stages of growth have been obtained from the beds. From Spitzbergen (78° 56' N. lat.) 136 species of fossil plants have been named by Heer. But the latest English Arctic expedition brought to light a bed of coal, black and lustrous like one of the Palaeozoic fuels, from 81° -15' lat. It is from ‘.35 to 30 feet thick, and is covered by black shales and sandstones full of land-plants. Heer notices 26 species, 18 of which had already been found in the Arctic Miocene zone. As in Spitzbergen, the conifers are most numerous (pines, firs, spruces, and cypresses), but there occur also the arctic poplar, two species of birch, two of hazel, an elm, and a Viburnum. In addi- tion to these terrestrial trees and shrubs the stagnant waters of the time bore water-lilies, while their banks were clothed with reeds and sedges. 'hen we remember that this vegetation grew luxuriantly within 8° 15’ of the North Pole, in a region which is now in darkness for half of the year, and is almost continuously buried under snow and ice, we can realize the difficulty of the problem in the distribution of climate which these facts present to the geologist. PLIOCENE. GREAT l3RITAIN.—The Miocene period seems to have passed away without any notable portion of the British Islands being depressed under the sea. Save the great outpouring of lava in the north-west, and the rise of hundreds of “ dykes ” of basalt along cracks of the crust in the north of England and throughout Scotland, the area of Britain seems to have remained as a part of the mainland of Europe, little affected by the subterranean movements which, as we have seen, were so potent among the Alps and in eastern Europe. At length the south—eastern counties began to subside, and on their submerged surface some sand- banks and shelly deposits were laid down, very much as similar accumulations now take place at the bottom of the North Sea. These formations are termed the Crag, and are subdivided, according to their proportion of living species of shells, into the following groups :— GEOLOGY [_v1. STRATI(‘:l‘.APIII(‘AL. . - _ (‘hillesford ("lay ......................... .. 1 to 8 ft. ““"°5f°"l b°‘l5 Chillesford Sand with shells... .. 5 ,, s ,, Norwich (fluvio-marine, niammaliferous) (‘rag ........... .. 5 ,, 10 ,, Red Crag .......................................................... .. .5 ,, 'hite (Suffolk, coralline) Crag ............................. ..40 ,, 60 ,, The White Crag consists of shclly sands and inarls. It contains 316 species of shells, of which 84 per cent. are still living. Among these are Ton-In-alula ‘r/2-«zzulis, Lin_{n([(& Dumorlieri, Peclen 0pe)'c2¢l«(ris, I ’/ml (alum 3/1: /1 is-Ierml, 1’_z/rula relic-ululu. The name corallinc was given to the formation from the innnense number of coral-like polyzoa which it contains, no fewer than 130 species having been described. The Red Crag is also a thin and local formation, consi.-ting of a dark—rerl or brown ferruginous shclly sand. f its mollusks, 92 per cent are believed to be still living species, and, out of :25 species of corals, 14 are still natives of British seas. Some of the typical shells of this subdivision are Troplzon anliqmmz (Fuszcs conlrtwius), l'olul«( ].«_nn/»cr(i, Purpura tclragona, Pecten opercnlaris, Pectmmzlus gly- cinzeris, and C_1/prina rustica. Numerous mamnmliau re- mains have been obtained from these sands, including bones of Jllrzslodon Arvernens1's and J[. trzpii-ozllas-, l;'/q»Iu(s me- ritlionalis, It’/1.-inoceros ScILlcz'ermacIter1', Tapirus pri.,-cus, Nus anliqzms, Equals plicideus, Ilipparion, I[_ 1/menu cuzlivlzlu, Ft [is pt_(7‘(l0i(l(’8, and Cerms anoceros. The Norwich or Fluvio- marine or .Iammaliferous Crag consists of a few feet of shclly sand and gravel, containing, so far as known, 139 species of shells, of which 93 pct‘ cent. are still living. About '20 of the species are land or fresh—water shells. The name of maminalifcrous was given from the large num- ber of bones, chieﬂy of cxtin ct species of elephant, recovered from this deposit. These fossils comprise J[u.s(u:lun .frvernensz's, Eleplms iizeridionalis, E. a2m'quu.-, a hippopo- tamus, horse, and dcer, likewise the living species of otter and beavcr. Onc intcresting feature in this formation is the decidcd mixture in it of nor!/tern species of shells, such as It’Iz_2/ncltonella psiltacea, Scalaria G'ra=nlumI-ion, and _-I.-(uric boreal-is. These may be regarded as the forerunners of the great invasion of Arctic plants and animals which, in the beginning of the Quaternary ages, camc southward into Europe, together with the severe climate of the north. The Chillesford beds occur likewise as a thin local deposit in Suffolk and Norfolk. Of the shells which they contain, about two-thirds still live in Arctic waters. It is evident that, in these fragmentary accumulations of the Crag series, we have merely the remnants of some thin sheets of shclly sands and gravels laid down in the shallow waters of the North Sea, while that great lowering of the European climate was beginning which culminated in the succeeding or Glacial period. C0.'TINE.'T.-L EUROPE.--Marine strata, sometimes of considerable thickness, were laid down over different portions of the liuropean area during the Pliocene period. The most extensive of these occur in Italy and Sicily; in the latter island they have since been up- heaved to a height of 3000 feet above the sea. They have likewise been raised into the chain of heights ﬂanking the Apcnnine Moun- tains, whcre they are known as the Subapennine series. In the shore watcrs and estuaries of that ancient Italy some of the same huge mammals lived as were contemporaneously denizens of England.— the Auvergnc mastodon. Rhinoceros Elruscus Elcphas nm'z'd[omzI2'-, Iiippopotamus major, with bears and hyzcnas. liastwards we obtain evidence of the gradual exclusion of the sea from the areas of the European continent which it had covered dm ing the Miocene period. The Congeria stage (above n-fen-ml to) of the Vienna basin brings before us the picture of an isolated gulf gr adu- ally freshening by the inpouring of rivers like the modern Caspian, but with bays nearly cut off from the main body of water, and un- dergoing so copious an evaporation without counterbalancing inflov that their salt was deposited over the bottom as in the Karaboghaz of the Caspian (ante, p. 279). TERTI.-I1Y Snares or Norrrn AMERICA. Tertiary formations of marine origin extend in a strip of low land along the Atlantic border of the United States,